1. Field of the Invention
This invention relates to a circuit designing device and a circuit designing method, and more particularly a circuit designing device and a circuit designing method in which a circuit configuration is changed in accordance with a genetic algorithm.
2. Description of the Related Art
In the case that a complex logical circuit for use in controlling a robot or the like was to be designed, a designer combined many basic logical elements to each other in accordance with his experience to design a logical circuit. However, in recent years, a method for designing a logical circuit without requiring any experience-based knowledge on the basis of a GA (genetic algorithm) has been introduced by Mr. Higuchi et al. as "a basic experiment of a hardware development through a genetic study" in the book entitled of "Genetic Algorithm (edited by Hiroaki Kitano, Sangyoh Tosyo Publishing Company)", for example.
In this prior art method, the circuit configuration of a PLD (Programmable Logic Device) represented by an FPGA (Field Programmable Gate Array) is repeatedly changed in response to the GA so as to make a logic device for performing a target output.
The PLD has a plurality of logical cells capable of dynamically selecting the type of basic logical calculations such as AND logical calculation, OR logical calculation or the like and can change the type of logical calculation performed by each of the logical cells and patterns of circuit connection between these logical cells.
In GA, items to cause the target to be most adapted are expressed by genes and then chromosome is generated by connecting these genes. Then, a plurality of chromosomes are repeatedly revised to cause the item to approach the most suitable state.
In the prior art, a function of the logical cell in the PLD and a pattern of circuit connection between the logical cells are expressed by chromosomes and the chromosomes (circuit configuration of PLD) are revised in response to GA so as to make a logical circuit performing a target output.